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In the present study, a magnetically separable adsorbent, manganese ferrite (MnFe

Reductive amination has not been commonly used in the preparation of N-alkylsulfonamides because of the low nucleophilicity of sulfonamides. In this work, a protocol for the synthesis of N-alkylsulfonamides from aldehydes or ketones and sulfonamides was developed. Molecular iodine, triethylsilane, and ethyl acetate were used as the initiator, reductant, and solvent, respectively. The key role of triethyl(iodo)silane in the reaction was confirmed through control experiments.

Plasticizers that enable flexible polyvinyl chloride (PVC) are usually combustible, restricting the application of PVC in fire-prone scenarios. In this context, intrinsically flame-retardant plasticizers displaying dual function continue to be the focus of intensive research. Despite their efficiency, the majority of these dual-functional plasticizers previously reported contain halogen elements, which, once ignited, emanate toxic and potentially carcinogenic substances, along with toxic gases and smoke, polluting the environment, damaging the biota, and threatening human health. Here, we report a strategy to obtain a halogen-free, intrinsically flame-retardant PVC bio-plasticizer that harnesses the phenolic hydroxyl of naturally occurring cardanol and covalent attachment of an organophosphate moiety. When combined with di-(2-ethylhexyl) phthalate (DOP), the organophosphate-containing cardanol is qualified as a co-plasticizer, while endowing the PVC materials with flame retardancy. Unlike inorganic flame-retardants, the engineered cardanol is compatible with PVC such that the mechanical properties of the PVC materials are not compromised. The rationale underlying the present effort may provide guidance for developing sustainable alternatives to halogen-containing plasticizers to address the sustainability challenge now confronting PVC industry.

Abstract As an imitation of genuine leather, polyvinyl chloride (PVC) artificial materials are versatile, but suffers from being flammable due to the presence of large amounts of combustible plasticizers. Under such circumstance, intrinsically flame-retardant plasticizers displaying dual functions have been a subject of intensive research interest. However, previous strategies attempting to covalently attach flame-retardant moiety to plasticizers invariably required either expensive starting materials or laborious and tedious procedures, ultimately limiting their scale-up application in industry. In addition, driven by escalating demand of halogen-free flame retardants worldwide from an environmental health perspective, previously reported intrinsically flame-retardant plasticizers were mainly halogen-free, less attractive in PVC artificial material industry simply because PVC itself is a halogen-containing polymer. Here, we report an approach to introduce chlorine moieties into unsaturated fatty acid methyl ester by a simple addition reaction occurring on carbon-carbon double bonds, yielding a chlorine-containing, intrinsically flame-retardant bio-plasticizer. When combined with di-(2-ethylhexyl) phthalate (DOP) in PVC formulations, the chlorinated fatty acid methyl ester is qualified as a co-plasticizer while conferring flame retardancy upon the PVC coatings. This approach involves only a one-step procedure that employs renewable fatty acid methyl esters and cheap chlorine gas as raw materials, thus being of great potential to enable intrinsically flame-retardant bio-plasticizers on a large scale to manufacture functional PVC artificial materials for application in fire-prone scenarios. Graphical abstract

Under physiological ionic strength and pH, temperature has long been appreciated as the only stimulus that can be applied to induce in vitro self-assembly of tropocollagen. Here, we report a second, mechanistically new control strategy that uses non-covalent and selective binding of cucurbit[7]uril, a macrocyclic cavitand, with midchain aromatic residues on the tropocollagen surface. This strategy directly demonstrates the decisive role hydrophobic interactions play in collagen fibrillogenesis. It also points the way to the temporally-controllable formation of collagen fibrils in vivo that is highly desirable, yet challenging, in some biomedical scenarios.

Like other historical preservation areas, the Fayuansi Community in Beijing’s old city zone faces many problems such as high population density and a shortage of public spaces. As a community that has lasted for more than a thousand years, its block pattern embodies the early historical pattern of Beijing city. Micro Small Public Spaces (MSPS) in the community are of great significance to the physical and mental health of residents, especially during the COVID-19 epidemic. This research investigates the habit shifts of residents’ usage of these spaces and introduces the theory of “Sense of Place”, which is a concept that refers to the manner in which individuals relate or feel about the place they live, and conducts a questionnaire survey of residents in the Fayuansi community. After analyzing the residents’ needs according to the survey, this study gives suggestions on the management of MSPSs, such as increasing the supply of both spaces and facilities, strengthening management, paying more attention to senior residents’ needs, and providing more cultural events. All these measures would strengthen residents’ sense of place and develop popular support for policy.

We prepared bio- and UV-degradable superabsorbent hydrogels based on a novel cross-linker. Fourier transform infrared, thermogravimetric (TG), differential scanning calorimetry (DSC), X-ray diffrac...

The safety of flexible polyvinyl chloride (PVC) materials is now being questioned, partially due to allegations that di-(2-ethylhexyl) phthalate (DEHP), the dominant PVC plasticizer, is an endocrine disruptor and a probable carcinogen. As sustainable alternatives, aliphatic ester-derived plasticizers feature low cytotoxicity, biodegradability, and renewability, but they can only partially replace DEHP in PVC formulations because they have a strong tendency to migrate. Here, using epoxidized fatty acid methyl esters and aliphatic diesters as representatives, we demonstrate that covalently attaching one short ester at each α-position of aliphatic esters via Claisen condensation with judiciously selected dialkyl carbonate significantly suppresses their migration from the PVC matrix. In certain scenarios, the engineered plasticizers even migrate at a rate comparable to, or improved beyond that of DEHP. This approach harnesses the α-proton, a structural feature shared by all aliphatic esters, and dialkyl carbonate, an established “green chemical”, thus providing a potentially general and green route towards DEHP alternatives with unprecedented performance that may contribute to sustainability of the old and oft-maligned PVC industry.

Digital terrain models based on light detection and ranging (LiDAR) are widely used in ground robots to achieve autonomous navigation. Very few studies have been conducted on terrain modelling for preview information, which acts as an input for a vehicle’s active suspension system. In this study, we proposed an algorithm to construct a real-time terrain model from multi-frame LiDAR points according to the applications for preview control. The terrain model consisted of an elevation map with confidence intervals and feature detection. First, the statistical confidence interval of the elevation map represented the reliability of the mean height. Further, we used spatial signal processing techniques to detect the uneven geometric features of the terrain. The key point feature on the trajectory was detected by the Laplacian of Gaussian method. Finally, the raw point cloud data processing procedure was based on parallel multi-thread techniques combined with GPU programming, which significantly promotes computation efficiency to enable real-time implementation. Thus, the proposed terrain model integrates reliability issues and geometric features, which act as inputs for preview controllers or motion planning. Experimental results proved that our method has a competitive performance (in terms of precision and efficiency) compared with the state-of-the-art methods, and runs in real-time at 50 Hz.

In this work, chitosan‑sodium alginate polysaccharide hydrogel (CS

The invasion front of oral squamous cell carcinoma (OSCC) harbors the most aggressive cells of the tumor and is critical for cancer invasion and metastasis. MicroRNAs (miRNAs) play important roles in OSCC progression. In this study, we modelled the OSCC invasion front on a microfluidic chip, and investigated differences in miRNA profiles between cells in the invasion front and those in the tumor mass by small RNA sequencing. We found that miR-218-5p was downregulated in invasion front cells and negatively regulates OSCC invasiveness by targeting the CD44-ROCK pathway. Thus, miR-218-5p may serve as a useful therapeutic target for OSCC. Moreover, invasion front cell isolation based-on microfluidic technology provided a useful strategy for cancer invasion study.

Matt polyurethane coating was successfully prepared through the synergistic effect of castor oil and phenolic epoxy resin into polyurethane backbone. The formation mechanism may be ascribed to the modulus mismatch between the partially modified epoxy polyurethane and partially unmodified polyurethane. Scanning electron microscopy (SEM) was used to observe the micro-rough surface morphologies. Atomic force microscopy (AFM) and three-dimensional (3D) surface profilometer were applied to calculate a series of surface roughness parameters in different dimensions, such as Sa, Sq, Sp, Sv, Sz, Sku, Ssk, etc. The exciting results of this paper&mdash, the correlation of surface roughness on measurement length and gloss&mdash, are explored in detail. It reveals the extrinsic property of measured roughness with measurement length and provides guidance for what kind of incident angle gloss meters (20&deg, 60&deg, and 85&deg, ) best describe the gloss of matt polyurethane coating.

Adaptation to endoplasmic reticulum (ER) stress has been indicated as a driver of malignancy and resistance to therapy in human melanoma. However, the relationship between cancer stem cells and adaptation to ER stress remains unclear. Here, we show that the ratio of cancer stem cells is increased in ER stress-resistant melanoma cells, which inhibit ER stress-induced apoptosis and promote tumorigenesis. Further mechanistic studies showed that HOXB9 triggered by ER stress favors cancer stem cell self-renewal and enhances ER stress resistance. HOXB9 directly binds to the promoter of microRNA-765 and facilitates its transcription, which in turn targets FOXA2, resulting in a FOXA2 decrease and cancer stem cell increase. Additionally, an increase in HOXB9 promotes melanoma growth and inhibits cell apoptosis in a mouse xenograft model. Elevated HOXB9 is found in human melanoma tissues, which is associated with microRNA-765 up-regulation and FOXA2 decreases. Thus, our data showed that the HOXB9-dependent, microRNA-765-mediated FOXA2 pathway contributes to the survival of melanoma under ER stress by maintaining the properties of cancer stem cells.

Nano-CuO have been grown on the surface of CdS nanorods by a simple solution-phase reaction, which greatly enhanced the hydrogen evolution ability of CdS. The physical chemistry properties of CuO/CdS nanocomposites were investigated by XRD, SEM, TEM, BET, XPS and electrochemical methods. The morphology and crystal structure of CdS were not influenced by the loading of Nano-CuO. And it was helpful to delay the time of electron recombination to the hole, and greatly improved the hydrogen evolution performance of CdS. When the loading of Nano-CuO was 1 wt%, the photocatalytic performance of CdS increases from 105 μmol g−1 h−1 to 3317.5 μmol g−1 h−1. After several cycles, the structure of CuO/CdS nanocomposites was not changed, and Nano-CuO could effectively prevent the photo-corrosion defects of CdS. This work provides a new way to improve the hydrogen evolution performance of CdS by growing nano-oxide on CdS surface.

Gallic acid (GA), with a reducing and in situ coordinating capability towards to reducible metal ions, was successfully conjugated onto the amine-silane coated magnetite nanoparticles by stable amide bond through 1-ethyl-3-(3-dimethylaminepropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) chemistry, with the aim of engineering a magnetically-separable Fe3O4@TEOS@AMEO@GA applicable for Cr(VI) concurrent reduction and removal, together with explicating reduction-adsorption mechanism. The structure, composition, and morphology of the nanocomposite were systematically characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), low-temperature nitrogen adsorption/desorption experiment, X-ray spectroscope (EDS), X-ray photoelectronic spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), total organic carbon (TOC), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and fluorescence spectra, showing a core-shell, cubic inverse spinel structure of the nanocomposite with superparamagnetism roughly containing 7.8% (w/w) GA on its surface. Cr(VI) reduction-adsorption kinetics, equilibrium, and thermodynamics studies were carried out under solution pH of 6.0, where partially deprotonated phenolic hydroxyl dominated the nanoadsorbent surface. Results showed that pseudo-first order kinetic model and Freundlich isotherm model described the Cr(VI) reduction-adsorption well. Thermodynamics studies indicated an endothermic, spontaneous, and feasible process of such Cr(VI) reduction-adsorption. Furthermore, Cr(VI) reduction-adsorption mechanism was explicated by EDS and XPS technology, finding that phenolic hydroxyls of those conjugated gallates were only functional and active groups. Based on these, we intend to offer a predictable, and hence controllable approach for Cr(VI) reductive immobilization that may be a potential direction for those poisonous and reducible metal ions thorough detoxification and in situ removal based on magnetite-supported materials in practical application.

In the field of plasma diagnosis, the measurement of the distribution function is significant because the distribution function is the basis for the use of plasma kinetic theory and it is the prerequisite for analyzing many physical phenomena, such as Landau damping (wave-particle resonance phenomenon) and ion sheath. Theoretical analysis and a large number of experiments have proved that plasma components do not obey Boltzmann–Gibbs statistics and can be well described by nonextensive statistical mechanics. The field of nonextensive electric probe has also made great progress, and the invention of the nonextensive single electric probes has developed and strengthened the power of plasma diagnostics. The nonextensive electric probe can not only measure the electron nonextensive parameter of plasma that cannot be measured by traditional probes but can also measure more accurate plasma parameters that can also be measured by traditional probes, such as Te, Φp, ne, Φf, and αqFe. However, diagnosing the plasma distribution function by the nonextensive electric probe has not been thoroughly and systematically analyzed and discussed. Here, we show the measurement of the plasma distribution function with a nonextensive single electric probe. This work expands the diagnostic capabilities of the nonextensive single electric probe. We utilize the nonextensive single electric probe theory to analyze the experimental data points of the I–V curve, measure the plasma electron distribution function fvx, and display the distribution curve (figure f-vx), and we also measure the plasma parameters of qFe, Te, Φp, ne, Φf, αqFe, etc. The proposed method provides a new approach to the diagnosis of the plasma distribution function and contributes to a more accurate and comprehensive grasp of plasma, which creates better conditions for us to take advantage of plasma. These initial results illustrate the potential of the nonextensive electric probe in the field of plasma diagnosis and, more generally, in accelerating the progress of fusion-energy science and helping to understand complex physical systems.

An epoxidized safrole, 5-(oxiran-2-ylmethyl)-benzo[d][1,3]dioxole (OYBD), was synthesized and employed to modify collagen for improving its antibacterial activity. The interaction between collagen and OYBD, and the structure/properties of the modified collagen were investigated in detail. The results indicated that the OYBD-modified collagen showed a higher de-nature temperature (Td, 90.2 °C), improved hydrophobic properties (contact angle from 84.2° to 89.1°) and enhanced tensile strength (6.2–11.0%) without destroying its triple helix structure. From observation of scanning electron microscopy (SEM), a higher density of intertwining morphology and a more stable network structure were observed, which was consistent with improved tensile strength and reduced breaking extension stress. The antibacterial test and LIVE/DEAD Baclight bacterial viability assay illustrated that the modified collagen exhibited excellent antibacterial activity to both Gram-negative and Gram-positive bacteria. Furthermore, the OYBD-modified collagen still exhibited cytocompatibility, supporting human fibroblast proliferation, which holds a great potential for developing antibacterial collagen-based biomaterials.

Fluoride contamination in water continues to be a great challenge to the sustainable development of global fluorine-containing industries. It is still a challenge to avoid the use of chemical desorbents induced secondary contamination in regenerating fluoride adsorbents. In this work, we aim to design a nanoadsorbent (SP@SiO2) specifically applicable for fluoride (F−) adsorption and desorption without using chemical desorbents, but via the approach of light-induction. The SP@SiO2 was fabricated by conjugating a rationally synthesised light-sensitive compound, spiropyran (SP), onto engineered mesoporous silica (SiO2) nanoparticles. Results showed that there was ∼0.14-0.15 mmol of SP conjugated onto per g of nanocomposite surface, forming a core-shell structure, which can realize conformational freedom of SP ↔ MC (merocyanine) transformation and corresponding adsorption and desorption fluoride under photo-controllable manner. Based on these, we intend to engineer a nanoadsorbent for F− remediation that may be potential guidance for those poisonous anions adsorption and light-induced desorption based on spiropyran-functionalized materials.

Whether an extra, subtle high-free-volume interphase in glassy polymers containing spherical nanoparticles really exists remains an open question, posing fundamental challenges for accurately predicting and intentionally tailoring the macroscopic transport behavior of these nanocomposites, which is crucial for a broad spectrum of industrial applications. Herein, we report new evidence supporting this controversial interphase by computational simulation and offer a generic framework for understanding how the interphase is shaped, based on a comparative strategy. This framework, validated by our previous experimental data, may provide guidance for rationally designing interfacial architectures in these nanocomposites that enable bottom-up tuning of their transport properties for specific applications.

Potential ecological risks of chromium(III) contaminates in tannery effluents have evoked considerable discussion and re-examination over the future role of chrome tannage, which has been long considered as the foundation of the modern leather industry. Despite previous magnetite-supported adsorbents for chromium removal, few of them were specifically engineered to address trivalent chromium, as well as the composition complexity in tannery effluents. Herein, gallic acid, a natural triphenolic compound capable of coordination to chromium(III), was covalently conjugated onto engineered magnetite nanoparticles via 1-ethyl-3-(3-dimethylaminepropyl) carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) chemistry, in an effort to design a magnetically separable nanoadsorbent applicable for remediating chromium(III)-contaminated tannery effluents. The structure of the nanoadsorbent was systematically characterized by multiple techniques, and the influence of pH value, adsorbent dose, temperature, and leather-related co-existing substances on its chromium(III) removal potency was investigated, respectively. Also, kinetics, equilibrium, and thermodynamics studies were conducted to decipher the mechanism by which chromium(III) cations were adsorbed. Finally, the feasibility of treating real tannery effluents that also contained high concentrations of sulfides, chlorides, ammonium nitrogen, total suspended solids, chemical oxygen demand (CODCr), and biochemical oxygen demand (BOD) by using the nanoadsorbent designed herein was explored. It was found that the chromium(III) removal percentage was approximately 95.2 ± 1.6%, and the exhausted nanoadsorbent could be conveniently separated from the effluents via a simple magnetic process. By chemical desorption, the nanoadsorbent was regenerable, and reusable for multiple cycles without a significantly compromised adsorption potency. According to these results, we aim at providing an efficient solution that may be a great addition to the ongoing fight against chromium(III) contamination in tannery effluents.

The environmental sustainability of existing adsorbents in remediating chromium-contaminated water has long been plagued by the necessity of using chemical desorbents in regenerating the adsorbents. Here, we demonstrate that trivalent chromium can be repelled from surface-bound merocyanine upon visible-light irradiation, avoiding any chemical desorbent, and thus secondary contamination, to restore the adsorption capacity of the exhausted adsorbents.

Bacterial resistance is emerging as a global threat, stemming partially from continuous exposure of pathogens to antibiotics of sublethal concentrations. Thus, novel molecular approaches capable of inactivating antibiotics, which prevent their final build-up in the environment, are highly desirable. Here, we report a proof-of-principle demonstration of a mechanically new strategy for switchable control of antibiotic activity, which regulates drug uptake across the outer membrane of Gram-negative bacteria by externally triggered shape shifting of a short, covalently attached “tail”. The rationale behind this strategy is grounded in the size-selectivity of porin channels exploited by a large proportion of antibiotics for accessing intracellular targets, thus representing a general approach to control antibiotic availability in the environment which alleviates undue selection pressure for resistance.

Widespread concern over antimicrobial toxicity and resistance development necessitates the thorough recovery of antimicrobial compounds from decontaminated collagen. Herein, ciprofloxacin molecules were acryloylated by reaction of the secondary amine in 7-piperazinyl substituent with acryloyl chloride, and then covalently immobilized, for the first time, on the vinyl-functionalized Fe3O4 nanoparticle surface via graft copolymerization with acrylic acid, in an effort to design a magnetically-recoverable nanocomposite potentially applicable for microbial decontamination of collagen solution. Unlike previous magnetite-supported antimicrobials invariably involving the release of antimicrobially-active component, these immobilized ciprofloxacin moieties proved non-leachable, in whole or in part, from the magnetite core, exerting antimicrobial activity as free ciprofloxacin, and thus could be thoroughly recovered from decontaminated collagen solution under magnetic fields. Also, it was found that the unique triple-helical conformation and, hence, bioactive properties of tropocollagens remained intact after decontamination using such recoverable antimicrobials. This proof-of-principle study aims to shed light on a long-standing dilemma in the collagen community: how to decontaminate collagen using antimicrobial compounds without being subject to antimicrobial residues?

By combining solvent evaporation with wet phase inversion technique, an asymmetric polyurethane membrane (ASPU) was constructed from a sulfanilamide-conjugated PU, as a potential candidate for wound dressing application. As a result of the combined membrane-formation method, the ASPU membrane was constituted by an integral and dense skin layer supported by a porous sublayer. The skin layer was found impermeable to pathogenic organisms, while the sublayer was intended for draining excessive exudates. Compared with typical PU membrane dressings commercially available, the ASPU membrane exhibited a reasonable moisture vapor transmission rate, as well as significantly improved gas circulation and exudate absorption capabilities, which synergistically optimized the wound microenvironment for proper healing. Furthermore, the sulfanilamide-conjugated PU constituting ASPU membrane was designed as susceptible to urease, a representative hydrolase derived from inflammation-causing pathogens. In the presence of urease, urea linkages adjacent to sulfanilamide monomeric units were found catalytically cleaved, enabling release of free antibiotic sulfanilamide that held pharmacological activity from ASPU membrane. When incubated without urease, those cleavage sites exhibited substantially high resistance against hydrolysis so that no sulfanilamide release was detected throughout the incubation period. In this inflammation-responsive manner, the anti-inflammatory efficiency of antibiotics was significantly enhanced, while undesirable side effects associated with antibiotic abuse was minimized. Cell culture assay further revealed that the ASPU membrane displayed no cytotoxicity toward normal human dermis fibroblasts, suggesting a biocompatible potential. Based on these results, the multifunctional ASPU membrane designed in this study might be clinically suitable as an ideal biomedical dressing for wound care.

This paper analyzes the satisfaction of residence conditions and public housing combining the online survey data of Tuosuo Company and Zero Company with public. The paper finds that the public dissatisfies with the old residential renovation, infrastructure maintenance and the construction of affordable housing. And then it analyzes the reasons of these dissatisfactions and proposes recommendations accordingly.